Variable-speed pulley structure



Dec. 19, 1939.I c. E. JoHNsoN l I 2,183,887

VARIABLE-SPEED PULLEY STRUCTURE Original Filed May l; 1933 `PatentedDec. 19, 1939 y vakman- SPEED rULpnxsfrnUc'rURE-I T V n nin,lCarl'EJohnsonyPasadena,'Calif.-

original'apueatiomjmay 1,; lsss'gffs-'rial No.

668,772." Divided and this application Decembert, y193'7, Serial'No.176,469 f Y 5S1vices adapted to drive machineryV at variableY speeds,and `relates particularly to. power d evices having variable-'diametertransmission means. The objects-:of my` present belt and'pulle'y leyssimple meanswhereby .the variable-diameterfpulleyror pulleys i'may bequickly and positively adjusted toproduce a desired speed of a poweroutput or power delivery shaft which is adapted to b e connected to apower utilizing device in accordance with the known practices ofcouplings, gearings, or belting; and to produce certain importantimprovements in theconstruction of variable-speed power devices ashereinafter set forth.

- A further object of the invention is to provide a power device whichvemploys a springf adjusted V-type pulley and is provided with means formoving a movable pulley flange thereof `axially in accordance with belttension changes.

' It is a further object of the invention to pro` vide a new andimproved V-belt pulley struc- -ture which may be mounted on a motorshaft and which will require a minimum of space outside the motorstructure. l A further. object of the invention is kto provide a noveland valuable spring-adjusted variable-diameter V-type pulley havingminimum space requirements when mounted on a motor shaft.` v

HIt is a further object of the invention to provide an electric motorhaving lahollow drive `shaft with a variable-diameter V-type pulley7mounted thereon, there being a spring Within the drive shaft andoperable to hold one of the flanges of the pulley in movable lrelationrelative to the other.

Further objects and advantages of the invention will be made evidentthroughout the following specification. i

Referring to the drawing, which is for illustrative purposes only,

Fig. 1 is a longitudinally, vertically sectioned ble-diameter pulleyapplied to a motor.

Fig. 2V is a longitudinally, vertically sectioned view showing analternative form of my springoperated variable-diameter pulley appliedto a motor.

invention Vare `n v :general toprovide in variable-speedpower deviceshaving one or more variable-diameter pl` View showing a form of myspring-operated varia- `In Fig.' i1, I show variable-diameterV-type'pulley I'I having aixe'd a motor I Il equipped with a outerange'-I2 'and an"axially movable inner" iiange' I3 ""1"Inl.thi's' form ofl`the invention the motor' I 0' is provided with a tubular` or hollowshaft vI5 having an opening I6 "extendingV from end 'toend thereof. In'the projecting end `I'I."

, of the 'tubular Yshaft I5, nearthe rightward-end of .the'motorILlongitudinal, diametrally Vopposed vslotsIIlare.Zplaceol, through whicha diametral pinll mayibe extendedsoas tobengage a hub LI'-formedfon theaxially movable' iiangeA I3.:- Within the axial opening I6 of the sha`tI.5,"a

sliding.4v block 2250i .cylindricalfforni isI placed, this block havinga diametral opening 23 through which the pin I9 passes. y A helicalspring 25 is placed in the axial opening I6 in' a position between thesliding block 22 and a threaded plug 26 adapted to screw into threads2'I formedwithin the leftward end of the shaft I5. The force with whichthe spring bears rightwardly against the block 22 may be varied byscrewing the plug 26 in or out of the threads 27 formed in the leftwardend of' the opening I6. The force of the spring 25 yieldably urges theaxially movable flange i3 toward the xed flange I2 which may befirmly'secured on thevextreme rightward end of the shaft I5 by use ofany` desired means. For this purpose, I have shownkey means 28 forpreventing ,rotation of the flange I2 relative to the shaft I5.

Relative rotation of the flangeA I3 is prevented by reason ofthe'engagement of the diametral pin or bolt I9 with the sidewalls of thediametral shown in Fig. 1 in the manner shown in Fig. 2,`

in which a motor 3B is provdedfwith an end bell or member 3l having acylindrical wall 32 set axially therein, this wall 32 having a smoothbore 33 in which-the outer race of a ball bearing 34 vmay slide axially.The inner race'35 of the bearing 34 is mounted on an axial sleeve 36 ina position to rest against a shoulder 31 formed on such sleeve 35. 'I hesleeve SSforms anuextended hub of 'an axially-movable flange A'38,- andAthe sleeve 36 has a bore` 40 Awhich slidably fits a motor shaft 4I, theleftward end of which motor shaft l is carried in abearing'lIZ securedthe leftward end bell 43 of the motor 30. In the assembly of partsshown, the sleeve 36 operates with or forms a slidable part upon therightwar-d portion of the shaft 4l, and the support of the rightward endof the shaft 4l is accomplished through engagement of the sleeve 36 withthe ball bearing 34. The rightward end 44 of the shaft 4l projects fromthe ange 38, and a fixed flange 41 is secured thereon. The rightward`portion of the shaft 4| is counterbored so as to provide an axialopening 45 therein to accommodate a spring 46 having the function offorcing rightwardly against a slide block 48 through which a diametralbolt or pin 50 extends. Between the end Wall 5l of the cylindrical Wall32 and the ange 38, the end .of the diametral pin 5D engages the sleeve36, and longitudinal slots 52 'are formed in the shaft 4| in diametrallyopposed position, through which slots 52 the pin 5l! passes and in whichslots the pin 50 is axially movable relative to the shaft 4 I. In thisform of the invention, the movement of the ange 38, due to the combinedactions of the spring 46 and the belt whichmay be employed in the V-slotof the pulley, correspondingly moves lthe sleeve 36 so as to bodily movethe bearing 34 in the bore 33 of the cylindrical Wall 32.

The shaft structure inA this manner produced is very rigid, and byfollowing this design the variable-diameter pulley .may be placed closeto the end of the motor sothat space requirements forv the pulley beyondthe end of the motor will be maintained at a minimum.

Although I have shown and described my in-V vention in simple andpractical form, it is recognized that certain parts or elements thereofarerepresentative of other parts, elements, or mechanisms which may beused in substantially the same manner to accomplish substantially thesaid pulley comprising a fixed ange rigidly securedto said shaft and amovable flange axially movable on said shaft; means connected to saidmovable flange and extending through said slot into said opening; vaspring member within said opening in said shaft for exerting a force onsaid means tending to move said movable flange axially relativeto saidfixed flange; a movable hub connected to said movable flange andjournalling said end of said drive shaft; a bearing xed to said hub andmovable therewith, said bearing sliding in a tubular flange secured tosaid motor, said bearing providing a radial bearing support for saidhub; and bearing means associated with said motor for supporting theother end of said motor shaft.

" CARL E. JOHNSON.

